/*
 *
 * @APPLE_LICENSE_HEADER_START@
 *
 * Copyright (c) 1999-2008 Apple Inc.  All Rights Reserved.
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_LICENSE_HEADER_END@
 *
 */
 /*
  *
  *  History:
  *      11-Feb-1999 Umesh Vaishampayan (umeshv@apple.com)
  *          Added atomic_or().
  *
  *      26-Oct-1998 Umesh Vaishampayan (umeshv@apple.com)
  *          Made the header c++ friendly.
  *
  *      12-Oct-1998 Umesh Vaishampayan (umeshv@apple.com)
  *          Changed simple_ to spin_ so as to coexist with cthreads till
  *          the merge to the system framework.
  *
  *      8-Oct-1998  Umesh Vaishampayan (umeshv@apple.com)
  *          Created from the kernel code to be in a dynamic shared library.
  *          Kernel code created by: Bill Angell (angell@apple.com)
  */

#ifndef _ATOMIC_H_
#define _ATOMIC_H_

#ifdef __cplusplus
extern "C" {
#endif

	/* Locking routines */

	struct spin_lock {          /* sizeof cache line */
		unsigned int lock_data;
		unsigned int pad[7];
	};

	typedef struct spin_lock* spin_lock_t;

	extern void spin_lock_init(spin_lock_t);

	extern void spin_lock_unlock(spin_lock_t);

	extern unsigned int spin_lock_lock(spin_lock_t);

	extern unsigned int spin_lock_bit(spin_lock_t, unsigned int bits);

	extern unsigned int spin_unlock_bit(spin_lock_t, unsigned int bits);

	extern unsigned int spin_lock_try(spin_lock_t);

	extern unsigned int spin_lock_held(spin_lock_t);

	/* Other atomic routines */

	extern unsigned int compare_and_store(unsigned int oval,
		unsigned int nval, unsigned int* area);

	extern unsigned int atomic_add(unsigned int* area, int val);

	extern unsigned int atomic_or(unsigned int* area, unsigned int mask);

	extern unsigned int atomic_sub(unsigned int* area, int val);

	extern void queue_atomic(unsigned int* anchor,
		unsigned int* elem, unsigned int disp);

	extern void queue_atomic_list(unsigned int* anchor,
		unsigned int* first, unsigned int* last,
		unsigned int disp);

	extern unsigned int* dequeue_atomic(unsigned int* anchor, unsigned int disp);

#ifdef __cplusplus
}
#endif

#endif /* _ATOMIC_H_ */
